Methods and apparatuses for providing services to a dual mode GPRS/WLAN or UMTS/WLAN WTRU

ABSTRACT

Methods and network nodes are described. A network node receives an attach request message from a wireless transmit/receive unit (WTRU) via a cellular radio access network (RAN). The attach request message includes a mobile station (MS) radio access capability information element (IE), and the MS radio access capability IE includes a field that indicates whether the WTRU is capable of receiving services from a core network via a non-cellular wireless access network. The network node provides services from the core network to the WTRU.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 13/285,746,filed Oct. 31, 2011, which is a continuation of application Ser. No.11/083,125, filed Mar. 17, 2005, which issued as U.S. Pat. No. 8,102,823on Jan. 24, 2012, which is a continuation of application Ser. No.10/750,193, filed Dec. 31, 2003, which issued as U.S. Pat. No. 6,940,844on Sep. 6, 2005, which claims the benefit of U.S. ProvisionalApplication No. 60/512,164, filed on Oct. 17, 2003, the contents ofwhich are hereby incorporated by reference herein.

FIELD OF INVENTION

The present invention relates to WTRUs having dual-mode capabilities andmore particularly to method and apparatus for reporting dual modecapabilities and for reporting availability of network interworking.

BACKGROUND

The current developments of wireless local area network (WLAN)interworking with general packet radio service/universal mobiletelecommunications system/third generation (GPRS/UMTS/3G) networks hasresulted in products that include two radio units in a common enclosure(e.g., cards supporting 802.11b+GPRS air interfaces and 802.11b+UMTS airinterfaces). The units may be separate cards or may be integrated ontoone common card.

Hereafter a wireless transmit/receive unit (WTRU) includes but is notlimited to a user equipment, mobile station, fixed or mobile subscriberunit, pager, or any other type of device capable of operating in awireless environment. When referred to hereafter, a base stationincludes but is not limited to a Node-B, site controller, access pointor any other type of interfacing device in a wireless environment.

Currently the network may not be aware of the dual-mode capabilities ofthe terminal. In addition, the offered services may change dramaticallybased on the terminal capabilities in terms of processing power, memoryavailability, screen size, bit rate, etc. For example, a dual mode802+GPRS personal digital assistant (PDA) may be able to receive shortmessage service (SMS) or multimedia message service (MMS) messages overa GPRS or an 802 network, however, several variations of these servicesmay be provided in accordance with allotted memory space of the wirelessterminal. Rich multimedia services may require larger memory size thanthat available in the PDA. Therefore, the same multimedia services maybe provided via black and white or a reduced set of colors depending onterminal capabilities. Also, the possibility of network-assisted handoffcan be provided to those terminals that indicate dual mode (WLAN/GPRS orWLAN/3G) capabilities. A mechanism is needed to indicate thesecapabilities to the existing GPRS/UMTS networks.

In addition, in network interworking, there is no capability ofinforming a wireless terminal having dual-mode radio capabilities andrelying upon one of the networks with which it communicates to beadvised of the interworking capability to enable the wireless terminalto have the increased ability of communicating with either of the twonetworks.

SUMMARY

Methods and network nodes are described. A network node receives anattach request message from a wireless transmit/receive unit (WTRU) viaa cellular radio access network (RAN). The attach request messageincludes a mobile station (MS) radio access capability informationelement (IE), and the MS radio access capability IE includes a fieldthat indicates whether the WTRU is capable of receiving services from acore network via a non-cellular wireless access network. The networknode provides services from the core network to the WTRU.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood from a consideration of thefigures in which like elements are designated by like numerals and,wherein:

FIG. 1 is a simplified schematic diagram of the network havingintegrated universal mobile telephone service (UMTS) and wireless localarea network (WLAN) networks.

FIG. 2 is a simplified schematic diagram showing an attached procedureand embodying the capabilities of the present invention.

FIG. 3 shows a WTRU network capability information element (IE).

FIGS. 4 and 5 respectively show the existing and modified networkcapability and radio access (RA) capability information element (IE).

FIG. 4A shows the modified network capabilities IE of FIG. 4 in greaterdetail.

FIGS. 5A1-5A2 and 5B show the modified RA capability IE of FIG. 5 ingreater detail and FIG. 5A shows the manner in which FIGS. 5A1 and 5A2are arranged.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The problem solved by this invention is the mechanism by which aterminal that supports both GPRS and WLAN, or 3G and WLAN can report itsWLAN capabilities to the supporting GPRS/UMTS networks. Also, theinvention identifies the mechanism by which a 3G network can indicatethat 3G or packet switched domain services over WLAN are available.

FIG. 1 shows a simplified block diagram of a network in which a UMTS anda WLAN are integrated. The WTRUs 12, 14 and 16 communicate with thenetwork over respective radio links (RL-1, RL-2 and RL-3). Moreparticularly, WTRU 12 communicates with a GSM radio access network(RAN); WTRU 14 communicates with a 2.5/3G RAN and WTRU 16 communicateswith a WLAN access point (AP). WTRUs 12 and 14 may be cellulartelephones while WTRU 16 may be a laptop, personal digital assistant(PDA) or other like device having an appropriate card enablingcommunication with the WLAN AP.

The GSM RAN communicates with a mobile switching center (MSC) which, asis known in the art, has the capability of interworking with locationdata bases. The MSC communicates with the visitor location register(VLR) to identify, authenticate, etc. the WTRU 12. The MSC alsocommunicates with the short message service-gateway mobile switchingcenter/interworking-mobile switching center (SMS-GMSC/IW-MSC) whichprovides the services such as short message service (SMS) data. The homelocation register (HLR) is a data base within the home public landmobile network (HPLMN) providing routing information for mobileterminated calls and SMS data and is also responsible for maintenance ofuser subscription information distributed to the relevant VLR (note theVLR in FIG. 1) or GSN (GPRS support node) through the attached processand mobility management procedures such as location area and routingarea updates.

The WLAN AP communicates with a packet data gateway/WLAN access gateway(PDG/WAG). Capability information is exchanged between the GSN and thePDG/WAG. Services such as SMS data services are communicated to thePDG/WAG and hence to the WTRU 16 by way of the PDG/WAG and WLAN AP.Based on the capability of the WTRU 16, SMS data may be deliveredthereto.

The WTRUs 12 and 14 when respectively communicating with the networkthrough their associated RAN, provide information regarding theircapability which, in accordance with the present invention, includesWLAN compatibility.

FIG. 2 shows an attached procedure combined with a WLAN capabilityupdate. In the procedure shown in FIG. 2, a UMTS dual mode WTRU, at stepS1, powers up for a signaling connection to perform the ATTACHprocedure. At step S2, a radio resource control (RRC) connection requestmessage is conveyed to the radio network controller (RNC). Admissioncontrol and availability of resources is performed by the RNC, at stepS3, which then conveys an RRC connection setup message to the dual modeWTRU, at step S4. The WTRU, at step S5, provides an RRC connection setup complete message providing the WTRU radio access (RA) compatibilityand, at step S6, provides the initial direct transfer message, whichincludes the attached request and the point-to-multipoint systeminformation (PtM SI), instant messaging system information (IM SI),network (NW) capability and radio access (RA) capability. The RNC, atstep S7, provides an initial WTRU Message: attach request including thenetwork and radio access capabilities. In addition to the UMTScapabilities, the message further contains WLAN capability. At step S8,authentication and ciphering request and security mode commands areperformed and the WTRU is authenticated, at step S9. Thereafter, theSGSN provides a WTRU capability update to the WAG-PDG, at step S10, andprovides an attach-accept message to the RNC, at step S11, which is thenconveyed, at S12, to the WTRU.

The update of the WTRU capability sent to WAG-PDG, at step S10, causesthe SGSN to update the WAG, which may then decide if the service requestcan be terminated.

The purpose of a mobile station WTRU network capability informationelement is to provide the network with information concerning aspects ofthe WTRU related to the GPRS. The contents of the information elementcan affect the manner in which the network handles the operation of theWTRU. WTRU network capability information indicates general WTRUcharacteristics and, except for fields explicitly indicated, isindependent of the frequency band of the sending channel.

WTRU network capability is a type 4 information element (IE) having amaximum length of ten octets.

The value part of the WTRU network capability IE is coded, as shown inFIG. 3.

FIG. 4 is a comparison of the existing network capability IE with thenetwork capability information element of the present invention and FIG.5 shows a comparison of the radio access capability information element(RAC IE) with the RAC IE of the present invention.

The purpose of the mobile station (MS) network capability IE is toprovide the network with information concerning aspects of the mobilestation (i.e., WTRU) related to GPRS. The contents can affect the mannerin which the network handles the operation of the mobile station. The MSnetwork capability information indicates general mobile stationcharacteristics and except for fields explicitly indicated, isindependent of the frequency band of the channel it is sent on. The MSnetwork capability is a type 4 information element with a maximum of tenoctets length. The value part of a MS network capability informationelement is coded as shown in FIG. 3.

Making reference to FIG. 4, which shows the network capability IE inamplified fashion, item (1) of both the existing and new IE, namely thesystem management capabilities by way of dedicated channels, are thesame. Item (2) listed in the existing and new IE, the system managementcapabilities by way of GPRS channels are the same. Item (3) in theexisting IE, and item (6) in the new information element, the UniversalMultiple—Octet Coded Character Set (UCS), USC2 16 bit coding support,are the same.

Item (4) in the existing IE and item (7) in the new IE, i.e. thesupplementary service screening indicator, are the same. The support oflocalized service area (SoLSA) capability, item (5) of the existing IEand item (8) of the new IE, are the same.

Item (6) in the existing IE, the revision level indicator, is the sameas item (9) in the new IE. Items (4) and (5) in the new IE, namely, thesystem management capability by way of the WLAN and the short messagesystem (SMS) item which identifies text only, text and animation, theinstant message service and the multimedia service as well as others areprovided to the WTRU, are not provided in the existing IE. Items (7)through (10) of the existing IE are omitted from the new IE and will notbe discussed herein for simplicity.

FIG. 4A shows the network capability IE in greater detail. For example,as shown in FIG. 4A, the location service (LCS) value added (VA)location request notification bit, (in binary format) is “0” when notsupported and is “1” when supported. WLAN capability is supported whenits binary bit is “1” and is not supported when in the “0” state. Thebit or bits identifying each capability are assigned predeterminedlocations with the IE. This is also the case for the RA capabilities.Also note that the GPRS encryption algorithm (GEA) capability bit is “0”when not supported and “1” when supported.

The purpose of the mobile station radio access (MS RA) capabilityinformation element (IE) is to provide the radio part of the networkwith information concerning radio aspects of the mobile station (i.e.,the WTRU). The contents can affect the manner in which the networkhandles the operation of the mobile station. The MS RA capability is atype 4 information element, with a maximum length of 52 octets. Thevalue part of a MS RA capability information element is coded as shownin FIGS. 5A and 5B.

FIG. 5 compares the existing and new radio access capability IEs. Items(1) through (4) of the existing IE, namely the access technology type,access capabilities, UMTS FDD RA technology capability and UMTS 3.84Mcps TDD RA technology capability, are identical to the items (1)through (4) in the new IE.

Items (5) and (6) in the existing IE are omitted from the new IE andhence will not be discussed herein for purposes of simplicity. Item (5)of the new IE does not appear in the existing IE and provides WLAN radioaccess capability which identifies the type of remote terminal, (such asPDA, laptop, phone, etc.), memory size, screen size, processing power,technology version (such as 802.11, 802.15, 802.16 and so forth),service profile, (such as SMS text only or text and animation), MMS,IMS, location, MBMS, and the like.

FIGS. 5A1-5A2/5B show the MS RA capability IE in greater detail. InFIGS. 5A1-5A2, the Access Technology type of four binary bits,represents the technology type used for access. Gaussian minimum shiftkeying (GMSK) is a form of frequency shift keying providing goodspectral efficiency. 8PSK is a modulation technique where the carrierexists in one of eight states. FIG. 5B shows the fields and binary datesfor identifying some of the capabilities. For example, a three bit fieldis used to identify WLAN 802 RA Technology wherein the technologysupported is identified by a particular combination of binary bits. Notethat no support of WLAN 80.xx technology is represented by “000,”support for WLAN 802.11b technology represented by “001” and so forth.As another example, the CDMA 2000 RA Technology capability is “0” whennot supported and “1” when supported.

A dual mode WTRU provides a WLAN capability report over its UMTS (orGPRS) network depending on whether the dual mode WTRU has WLAN/UMTS orWLAN/GPRS capability.

As shown in FIG. 2, when the WTRU is powered up, it first communicatesby way of the UMTS channels and performs a non-access stratum (NAS)“ATTACH” procedure whereupon the UMTS/WLAN capability is exchanged withthe network, as shown in FIG. 2.

Depending on implementation, the user may chose to continuecommunicating with the UMTS network, manually switch over to WLANchannels or perform an automatic handover to the WLAN network, ifavailable.

The present invention thus introduces two new IEs to existing GPRS/UMTScapability messages between WTRU and network and network and WTRU. Theradio access capability information element (RAC IE) is modified toinform the network about the dual-mode capabilities of the WTRU/card,i.e., GPRS+WLAN or UMTS/WLAN. The radio access capability (RAC), carriesall aspects of the WLAN capabilities including terminal type, (such asPDA, laptop, cell phone), memory size, screen size, processing power,technology version (such as 802.11, 802.15, 802.16 and so forth),service profile (such as SMS text only or text and animation), SMS, MMS,IMS, location, multicast broadcast media service (MBMS) and so forth.The WLAN capability update procedures are achieved without modificationof the existing “ATTACH” procedure. The network capability is modifiedto inform dual mode WTRUs regarding the existence of WLAN interworkingcapabilities and the different types of services that can be providedover a WLAN network.

What is claimed is:
 1. A method for use in a network node, the methodcomprising: the network node receiving an attach request message from awireless transmit/receive unit (WTRU) via a cellular radio accessnetwork (RAN), wherein the attach request message includes a mobilestation (MS) radio access capability information element (IE), andwherein the MS radio access capability IE includes a field thatindicates whether the WTRU is capable of receiving services from a corenetwork via a non-cellular wireless access network; and the network nodeproviding services from the core network to the WTRU.
 2. The method ofclaim 1, wherein the network node is a Serving General Packet RadioService (GPRS) Support Node (SGSN).
 3. The method of claim 1, whereinthe non-cellular wireless access network is a wireless local areanetwork (WLAN).
 4. The method of claim 1, wherein the MS radio accesscapability IE further includes: an RF Power Capability field; aMultislot capability field; an 8PSK Power Capability field; a COMPACTInterference Measurement Capability field; a Revision Level Indicatorfield; a UMTS FDD Radio Access Technology Capability field; a UMTS 3.84Mcps TDD Radio Access Technology Capability field; a UMTS 1.28 Mcps TDDRadio Access Technology Capability field; and a Modulation basedmultislot class support field.
 5. The method of claim 1, wherein thecellular radio access network is based on Global System for MobileCommunications (GSM) or Universal Mobile Telecommunications System(UMTS) technology.
 6. The method of claim 1, wherein the services areprovided via the cellular RAN.
 7. The method of claim 1, wherein theservices are provided via a non-cellular wireless access network.
 8. Themethod of claim 1, further comprising the network node providing anattach accept message to the WTRU responsive to the attach requestmessage.
 9. A network node comprising: a receiver configured to receivean attach request message from a wireless transmit/receive unit (WTRU)via a cellular radio access network (RAN), wherein the attach requestmessage includes a mobile station (MS) radio access capabilityinformation element (IE), and wherein the MS radio access capability IEincludes a field that indicates whether the WTRU is capable of receivingservices from a core network via a non-cellular wireless access network;and a processor and a transmitter configured to provide services fromthe core network to the WTRU.
 10. The network node of claim 9, whereinthe network node is a Serving General Packet Radio Service (GPRS)Support Node (SGSN).
 11. The network node of claim 9, wherein the MSradio access capability IE indicates whether the non-cellular wirelessaccess network is a wireless local area network (WLAN).
 12. The networknode of claim 9, wherein the MS radio access capability IE furtherincludes: an RF Power Capability field; a Multislot capability field; an8PSK Power Capability field; a COMPACT Interference MeasurementCapability field; a Revision Level Indicator field; a UMTS FDD RadioAccess Technology Capability field; a UMTS 3.84 Mcps TDD Radio AccessTechnology Capability field; a UMTS 1.28 Mcps TDD Radio AccessTechnology Capability field; and a Modulation based multislot classsupport field.
 13. The network node of claim 9, wherein the cellular RANis based on Global System for Mobile Communications (GSM) or UniversalMobile Telecommunications System (UMTS) technology.
 14. The network nodeof claim 9, wherein the processor and transmitter are configured toprovide the services via the cellular RAN.
 15. The network node of claim9, wherein the processor and transmitter are configured to provide theservices via a non-cellular wireless access network.
 16. The networknode of claim 9, wherein the processor and transmitter are furtherconfigured to generate and transmit an attach accept message to the WTRUresponsive to the attach request message.
 17. A method for use in anetwork node, the method comprising: receiving an attach request messagefrom a wireless transmit/receive unit (WTRU), the attach request messageindicating a request to attach to a cellular core network and includinga capability indicator that indicates whether the WTRU is capable ofreceiving services from the cellular core network via a wireless localarea network (WLAN); and providing services to the WTRU based on thecapability indicator.
 18. The method of claim 17, wherein the servicesare provided via a cellular radio access network.
 19. The method ofclaim 18, wherein the cellular radio access network is based on GSM orUMTS technology.
 20. The method of claim 17, wherein the capabilityindicator is a radio access capability information element or a mobilestation (MS) network capability information element.
 21. The method ofclaim 17, wherein the services are provided via a wireless local areanetwork (WLAN).
 22. The method of claim 17, further comprisingproviding, to the WTRU, an acknowledgement of the attach requestmessage.
 23. A network node comprising: a receiver configured to receivean attach request message from a wireless transmit/receive unit (WTRU),the attach request message indicating a request to attach to a cellularcore network and including a capability indicator that indicates whetherthe WTRU is capable of receiving services from the cellular core networkvia a wireless local area network (WLAN); and a processor andtransmitter configured to provide services to the WTRU based on thecapability indicator.
 24. The network node of claim 23, wherein theprocessor and transmitter are configured to provide the services via acellular radio access network.
 25. The network node of claim 24, whereinthe cellular radio access network is based on GSM or UMTS technology.26. The network node of claim 24, wherein the capability indicator is aradio access capability information element or a mobile station (MS)network capability information element.
 27. The network node of claim24, wherein services are provided via a WLAN.